Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
Linux Linux — nvmet-tcp: fix incorrect locking in state_change sk callback
AV AC PR UI S C I A CVSS EPSS %ile KEV
L L L N U N N H 5.5 .0049 40.2 —
AFFECTED
Product Versions Fixed
Linux 872d26a391da92ed8f0c0f5cb5fef428067b7f30 – —
Linux 5.0 – 5.4.119
TIMELINE
Feb 27 Reserved by Linux
Feb 28 Published (CNA: Linux)
Aug 4 RESCORED — CVE-2021-47041 (Linux). CVSS 7.5 → 5.5 (NVD).
Description
In the Linux kernel, the following vulnerability has been resolved:
nvmet-tcp: fix incorrect locking in state_change sk callback
We are not changing anything in the TCP connection state so
we should not take a write_lock but rather a read lock.
This caused a deadlock when running nvmet-tcp and nvme-tcp
on the same system, where state_change callbacks on the
host and on the controller side have causal relationship
and made lockdep report on this with blktests:
================================
WARNING: inconsistent lock state
5.12.0-rc3 #1 Tainted: G I
--------------------------------
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-R} usage.
nvme/1324 [HC0[0]:SC0[0]:HE1:SE1] takes:
ffff888363151000 (clock-AF_INET){++-?}-{2:2}, at: nvme_tcp_state_change+0x21/0x150 [nvme_tcp]
{IN-SOFTIRQ-W} state was registered at:
__lock_acquire+0x79b/0x18d0
lock_acquire+0x1ca/0x480
_raw_write_lock_bh+0x39/0x80
nvmet_tcp_state_change+0x21/0x170 [nvmet_tcp]
tcp_fin+0x2a8/0x780
tcp_data_queue+0xf94/0x1f20
tcp_rcv_established+0x6ba/0x1f00
tcp_v4_do_rcv+0x502/0x760
tcp_v4_rcv+0x257e/0x3430
ip_protocol_deliver_rcu+0x69/0x6a0
ip_local_deliver_finish+0x1e2/0x2f0
ip_local_deliver+0x1a2/0x420
ip_rcv+0x4fb/0x6b0
__netif_receive_skb_one_core+0x162/0x1b0
process_backlog+0x1ff/0x770
__napi_poll.constprop.0+0xa9/0x5c0
net_rx_action+0x7b3/0xb30
__do_softirq+0x1f0/0x940
do_softirq+0xa1/0xd0
__local_bh_enable_ip+0xd8/0x100
ip_finish_output2+0x6b7/0x18a0
__ip_queue_xmit+0x706/0x1aa0
__tcp_transmit_skb+0x2068/0x2e20
tcp_write_xmit+0xc9e/0x2bb0
__tcp_push_pending_frames+0x92/0x310
inet_shutdown+0x158/0x300
__nvme_tcp_stop_queue+0x36/0x270 [nvme_tcp]
nvme_tcp_stop_queue+0x87/0xb0 [nvme_tcp]
nvme_tcp_teardown_admin_queue+0x69/0xe0 [nvme_tcp]
nvme_do_delete_ctrl+0x100/0x10c [nvme_core]
nvme_sysfs_delete.cold+0x8/0xd [nvme_core]
kernfs_fop_write_iter+0x2c7/0x460
new_sync_write+0x36c/0x610
vfs_write+0x5c0/0x870
ksys_write+0xf9/0x1d0
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x44/0xae
irq event stamp: 10687
hardirqs last enabled at (10687): [<ffffffff9ec376bd>] _raw_spin_unlock_irqrestore+0x2d/0x40
hardirqs last disabled at (10686): [<ffffffff9ec374d8>] _raw_spin_lock_irqsave+0x68/0x90
softirqs last enabled at (10684): [<ffffffff9f000608>] __do_softirq+0x608/0x940
softirqs last disabled at (10649): [<ffffffff9cdedd31>] do_softirq+0xa1/0xd0
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(clock-AF_INET);
<Interrupt>
lock(clock-AF_INET);
*** DEADLOCK ***
5 locks held by nvme/1324:
#0: ffff8884a01fe470 (sb_writers#4){.+.+}-{0:0}, at: ksys_write+0xf9/0x1d0
#1: ffff8886e435c090 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x216/0x460
#2: ffff888104d90c38 (kn->active#255){++++}-{0:0}, at: kernfs_remove_self+0x22d/0x330
#3: ffff8884634538d0 (&queue->queue_lock){+.+.}-{3:3}, at: nvme_tcp_stop_queue+0x52/0xb0 [nvme_tcp]
#4: ffff888363150d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: inet_shutdown+0x59/0x300
stack backtrace:
CPU: 26 PID: 1324 Comm: nvme Tainted: G I 5.12.0-rc3 #1
Hardware name: Dell Inc. PowerEdge R640/06NR82, BIOS 2.10.0 11/12/2020
Call Trace:
dump_stack+0x93/0xc2
mark_lock_irq.cold+0x2c/0xb3
? verify_lock_unused+0x390/0x390
? stack_trace_consume_entry+0x160/0x160
? lock_downgrade+0x100/0x100
? save_trace+0x88/0x5e0
? _raw_spin_unlock_irqrestore+0x2d/0x40
mark_lock+0x530/0x1470
? mark_lock_irq+0x1d10/0x1d10
? enqueue_timer+0x660/0x660
mark_usage+0x215/0x2a0
__lock_acquire+0x79b/0x18d0
? tcp_schedule_loss_probe.part.0+0x38c/0x520
lock_acquire+0x1ca/0x480
? nvme_tcp_state_change+0x21/0x150 [nvme_tcp]
? rcu_read_unlock+0x40/0x40
? tcp_mtu_probe+0x1ae0/0x1ae0
? kmalloc_reserve+0xa0/0xa0
? sysfs_file_ops+0x170/0x170
_raw_read_lock+0x3d/0xa0
? nvme_tcp_state_change+0x21/0x150 [nvme_tcp]
nvme_tcp_state_change+0x21/0x150 [nvme_tcp]
? sysfs_file_ops
---truncated---
Lifecycle
Complete event history — 3 events, chronological
| Date | Event | Detail |
| February 27, 2024 | Reserved | Reserved by Linux |
| February 28, 2024 | Published | Published (CNA: Linux) |
| August 4, 2026 | RESCORED | RESCORED — CVE-2021-47041 (Linux). CVSS 7.5 → 5.5 (NVD). |
Affected
Affected products and packages — 2 rows
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
| Linux | Linux | — | 872d26a391da92ed8f0c0f5cb5fef428067b7f30 | — |
| Linux | Linux | — | 5.0 | 5.4.119 |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2021-47041 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.